Journals of Gerontology Series A: Biological Sciences and Medical Sciences, Vol 50, Issue 6 B391-B398, Copyright © 1995 by The Gerontological Society of America
Time course of hypertrophic adaptations of the anterior latissimus dorsi muscle to stretch overload in aged Japanese quail
JA Carson, SE Alway and M Yamaguchi
Department of Exercise Science, Ohio State University, USA.
The purpose of this study was to determine if aged Japanese quail
demonstrated an altered time course of change in the morphology of the
anterior latissimus dorsi (ALD) muscle during the first two weeks of
hypertrophy induced by stretch overload. The left wing of adult (12 weeks
of age) and aged (90 weeks of age) birds were weighted with 10% of their
body weight; the right wing served as the intra-animal control. Thirteen to
sixteen birds from each age group were killed after 7 and 14 days of
stretch overload. Total fiber number was quantified by counting all the
fibers in a transverse section from the mid-belly of the ALD muscle. The
aged ALD retained the ability to increase the mass and total fiber number
of the stretched ALD after 7 (82%, 16%) and 14 (102%, 19%) days of stretch
overload. However, there was a main effect of age on the capacity to
increase muscle mass and total fiber number after stretch overload. These
results suggest that aging diminishes the increase and alters the time
course of adaptation in fiber number and myofibrillar mass of the stretch
overloaded ALD during the first two weeks of stretch overload.
